40265781 has 4 divisors (see below), whose sum is σ = 53687712. Its totient is φ = 26843852.

The previous prime is 40265773. The next prime is 40265821. The reversal of 40265781 is 18756204.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40265781 - 2³ = 40265773 is a prime.

It is a super-2 number, since 2×40265781² = 3242666239079922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40265681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6710961 + ... + 6710966.

It is an arithmetic number, because the mean of its divisors is an integer number (13421928).

Almost surely, 2^40265781 is an apocalyptic number.

It is an amenable number.

40265781 is a deficient number, since it is larger than the sum of its proper divisors (13421931).

40265781 is a wasteful number, since it uses less digits than its factorization.

40265781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13421930.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 40265781 is about 6345.5323653733. The cubic root of 40265781 is about 342.7509830306.

The spelling of 40265781 in words is "forty million, two hundred sixty-five thousand, seven hundred eighty-one".